1. Field of the Invention
This invention relates to a buckle used for connection of belts attached to a helmet, a life jacket and a rucksack or the like.
2. Description of the Prior Art
Heretofore, as disclosed in a laid-open specification No. Sho 62-24721 of Japanese Utility Model Reg. Application, a buckle wherein a base connected to a first belt is connected by means of a plug to a socket connected to a second belt has been well known.
Stating more specifically, as shown in FIG. 1, a belt 2 connected to a first belt 1 consists of a base plate 3 having a hole 4 formed therein, and a socket 6 connected to a second belt 5 consists of a flat plate 7 having a U-shaped engaging projection 8 formed thereon so as to form an aperture 9 between the projection 8 and the flat plate 7. Further, a plug 11 connected to a third belt 10 is formed into a flat plate adapted to be inserted in the aperture 9. The arrangement is made such that the projection 8 is fitted in the hole 4, and the plug 11 is inserted in the aperture 9 of the projection 8 projecting from the base plate 3 of the base 2 to thereby connect the base 2 with the socket 6.
In this buckle, the base 2 can be detached from the socket 6 by pulling out the third belt 10 to draw out the plug 11 from the aperture 9.
In such a buckle, however, the plug 11 is inserted in the aperture 9 of the projection 8 to connect the base 2 with the socket 6. Since the plug 11 is merely a flat plate and is held only by the friction resistance between it and the aperture 9 so as not to be drawn out, the plug 11 is liable to be drawn out from the aperture 9, and hence the base 2 cannot be connected securely to the socket 6.
Further, when the base 2 is detached from the socket 6, the plug 11 is detached from the base 2. Therefore, when the plug 11 is inserted in the aperture 9 of the projection 8 on the base plate 3 of the base 2, positioning of the plug 11 relative to the aperture 9 is troublesome and requires much trouble for connecting the base 2 with the socket 6.
To solve this problem, the inventor of the present invention has filed a Japanese Utility Model Reg. Application for buckle wherein, as shown in FIG. 2, a base 2 is formed with guide grooves 12 along which a plug 11 is slidably fitted in, and the plug 11 is formed with a pair of resilient pieces 13, 13 so that the sliding movement of the plug 11 along the guide grooves 12 enables the pair of resilient pieces 13, 13 to make snap fit into or to be withdrawn from the aperture 9 of the engaging projection 8 of the socket 6.
In such a construction, since the plug 11 can be engaged securely with the aperture 9 so as not to slip out of it, and when the base 2 is detached from the socket 6 the plug 11 can be held on the base 2 and inserted and engaged with the aperture 9 by moving it along the guide grooves 12, a strong connection of the base 2 and the socket 6 can be achieved, and also the connecting operation of the base 2 and the socket 6 can be made readily.
In this buckle, however, since the plug 11 is slidably moved freely by a small force along the guide grooves 12, when the third belt 10 is pulled out in the direction shown by arrow so as to withdraw from the aperture 9, there is a possibility of the plug 11 striking against stopper portions 2a of the base 2, and the resultant reaction force causing the resilient pieces 13 to spring back to the position of the aperture 4, or the plug 11 sliding by its own weight. Therefore, upon connecting the base 2 and the socket 6 again, it is required to slidably move the plug 11 towards the stopper portions 2a to enable the engaging projection 8 to be fitted in the hole 4, thus making the connecting operation of the base 2 and the socket 6 troublesome.